The purpose of this grant request is to help support an international workshop entitled "Chemoprevention of Human Cancer" to be held January 12-15, 1988 in Tucson, Arizona. This conference is the third in a series (1982, 1985) which has addressed issues related to the prevention of human cancer. This current conference is intended to review and discuss the status of the field of chemoprevention. The major areas to be covered include: the principles and scientific basis for human chemoprevention, measurement and pharmacology of chemopreventive agents, new (non-retinoid) chemopreventive agents, and methodologic issues for clinical chemoprevention trials. Fourteen prominent scientists from major disciplines including cell biology, biochemistry, pharmacology, nutrition, epidemiology, and clinical trials have accepted invitations to participate. At least 150 scientists are anticipated to be in attendance, in addition to invited speakers. From critical analysis of the existing data, new ideas and concepts will be generated for future studies concerning the role of dietary and pharmacologic manipulations in the prevention of the malignant human phenotype.